Thickener apparatus



.bmg-14,1945.l J. H. v. FINNEY' 2,382,409

THICKENER APPARATUS 'Filed sept..A 28, 194'2 v 4 sheets-sheet 2` Aug.14, 1945.

JQ H. y. FINN'EY THICK'ENERAPARATUS Y Filed sept. 28.- 1942 4sheets-sheet s karound the Scrapers.`

vor after shutdowns'has `been feasible.V

Patented ug. 14, 1945 THIoKENEn APPARATS John Il. V. Finney,` Denver,Colo.,` assignorvto i Mining Process and Patent Company, Denver, i r Ic0010., a corporation of Delaware,` N Application September 28, 1942,Serial No. `453,909

' 12 claims. i ol. 21u- 55) Ihisinvention relates to Settling apparatusfor the treatment of solids in yliquids and more particularly relates totraction-type thickeners.

Such-apparatus `providesa quiescent pool in which solids settle freelythrough the liquid `and deposit onto a bottom; usually conical, aboveand in proximity to Which,rotary scrapers move at slow speed to directthe settled solids toa dis- 1 charge outlet centrally of the bottom.

Industrial demands necessitate the production of such `apparatus yin awide variety of sizes. Wherethe diameter of the tank is forty feet 'orless, it usually is expedient to drive the scraper assembly throughtheintermediary ofia central shaft suitablyvconnected with a prime mover.

However, when larger sized tanks are specified,

such obstructionsand thus avoid damage `to the mechanism.

, While suchanarrangement has been incorpo`` rated into central drivevshaftA Vthickener i mech-` anism',` the design of the traction typemechanism has not been adapted to utilization of theseflifting features.s r u. It is an object ofthe presentinvention to provide". traction-typeactuating mechanism for thickenersi having simple. eicie-nt and`economi-` cal means kfor elevating'the associated scraper andparticularly those of a diameter of` onehunu dred feet-:or larger,ltraction drivemechanism `is employed to avoid subjecting` the `centralshaft to undue stresses. In `such a structure, a supporting trussmemberis pivotally mounted on a central column in the tank, and has oneor more of `its ends mounted onl a wheel-supported carriage traveling onan endless `track on the rim of the tank. i 4 g Thesecarriages1constitute vthe driving members of the assembly and carrymotors for` driving' the wheels. The Scrapers` :are suspended from thetruss structure `for conjoint rotation therewith and rotate at afxeddistance above the bottom.V

All of `the device-sy hereinbefore described are subjected to occasionalor intermittent shutdowns due to power failure or other causes, and whenthe stoppageis of i any considerable duration, the settled solids form avery compact and inert mass all In the central drive shaft designs,y thedeleterious effects of the `resistance of such a mass are avoidedthrough the provision `of lifting mechanism by which `the rakes can beelevated to approximately the iop of. the ,settled body, `and then afterthey are rotating they are allowedr to descend gradually to vtheirnormaloperating posi-y tions. `Asfaiconsequence.'undue stresses on thedriving mechanism are avoided. r i

Unlike the central shaft type, the traction type` mechanism has been sodesigned heretofore that no meansfor elevating the rakes duringoperation This Con"- dition has another disadvantage in thatobstructions sometimes develop during normal operation, due to thepresence of rocksg'tramp iron and'the likev whichfoccas'ionally 1enterthe tank. If the fakes were selfelevating, they could` ride .up overAnother objectl of` fthe' invention is to providel traction-typeactuating` mechanism for thickeners,` inclusive of self-elevatingscraper members.

d Ajfuriner bbjectoi trie inventionis tpiprevidetractionltypeactuatingmechanism in which the associated scraper membersmay be selectively and/or differentiallyspaced fromthe bottom of thetank in whichtheyV are positionedat different distancesfrom the `axis ofrotation., 1 J Qther objects" reside in novel combinations andarrangements of, `partsland in novel `details of construction,alllofwhich will be described inthe course. of the u followingdescription.

fro afford-a beiterjunderstanding afi-.he intention reference willbemadeto the accompanying `drawings `illustrating typical embodiments ofthe inventio`n` ,In the x drawings in the' several` 'views of which likepartsl have beendesignated'simiA lain; "l y lV Figure 1 is averticalcentral section through a thickener tank including mechanismembodying featuresof the present invention;` E y Figure2 isa fragmentarytop plan `vievvgof one embodiment of the mechanism of thepresent irl--`ve'ntion, partially broken to showconce'aled partsy and drawnfto anenlarged scale;

Figure 3" is a fragmentary `sideelevation partially in section andcorresponding to the Aappa-v ratus of Figure2; f

Figuresis a section taken along the line 4-4,` Figure 3;.af1d

i Figure 5 is another fragmentary side elevation partiallyl in sectionof another embodimentof the mechanism of the present invention,v alsodrawn to an enlarged scale.

` Referring iirst to Figure 1, the thickener comprises a tank 1` havingan upright peripheral wall 8,'supporting atits top anendless track 9andlpro-` vided With an Overflow launder l0 extending alon the top ofthe inner` surface of wall 8. 1

Thebottom Il` of tank 1 1s corneal and -ports a column l2 at its centerabout which an annular sumpl`3 is provided to collect the solids idescending along the conical bottom. Solids collecting in sump I3 aredrawn off through a suitable valve-controlled conduit I4 by the actionof a pump (not shown) Preferably, the conduit I4 and its associatedvalves are located in a tunnel I5 beneath the bottom II of the tank,which permits access for able arrangement of structural members, hereshown as consisting of four 'radial members disposed at 90 intervals.Two of these members positioned in lengthwise alinement areV relativelyshortas indicated at I'Ia in Figure 2, while the other two coact to forma tank spanning member, one or more of the outer ends of which aresuitably connected as shown at I8, to a wheelsupported carriage I9mounted on track 9. Each carriage has a motor in driving connection withits wheels 2l and it will be understood that suitable speed reductionmechanism may be included in the motor transmission system to rotate thetruss at the desired speed.

The center of the rtruss is journaled on a suitable bearing 2'I mountedon the top of the column or Apier I2 and the upper portion of this pieris enclosed by a feed well 22. I'he truss I'Icomprises a rectangularframework` suitably braced in a manner well known in the art.

In order to provide access to the bearing 21 and feed well 22, as wellas the main truss sections II, a walkway truss is suspended above themovable truss by attachment to the central column I2 as indicated at 23,anda second support 24 located beyond the peripheryof-the tank.`

Feed to the wellk 22 is supplied by ka conduit 26 supported beneathwalkway truss 25 -which discharges into the feed, well. throughga hollowcylinder 29 having openings into the feed well. Adjacent to the feed, aseries of slip Vrings 28 are provided which carry electric currentstationary power lines (not shown) to rotating lines on thetruss whichare connected to the motor 29.

'Scraper members 30 are supported in depend-- ing relation from truss IIVforconjoint rotation therewith and carry a plurality of blades 3lposi-- tioned at an inclination to their paths of movement and in closeproximity to thebottom II -to push settled. solids thereon toward randinto sump I3. These Scrapers are made in` separate sections designated30A, 30B and 30C inFigureB,

but it will be understood that any desired number of such sections maybe employed and this number usually will -be varied as the size oftheterminating above theliquid level in'an eyelet 3'5.

The beams 32 also are held by two parallel braces 36.and 31 pivoted on aside bar of truss I1 as indicated at 38 *and 39 respectively in'Figurev4 and pivotally connected with the beam as-.indicated at M and 4|.

By this arrangement, the position of the beam 32 remains unchangedupright or vertical throughout the range of its angular movement, whichis an arcuate path substantially at right angles to the lengthwise axisof the truss, as is 'clearly shown in Fig. 4, and this is true whetherIand the manner of suspending Scrapers 30 through the intermediary ofbeams 32, such oppo- Vsitionto forward movement induces a self-elevatingcomponent into the scraper assembly with vthe results that the blades 3|encountering the obstruction rise above the obstruction whereupon theyare free to settle again to normal operating position determined by thelocation of stops '33.

Likewise, after shutdowns, this feature permits an operator tostand onwalkway truss 25 and hook onto an eyelet 35 with suitable liftingmechanism such as a block and tackle assembly for example, and thusmanually raise the Scrapersl over obstructions or for positioning theScrapers albove or on top of a bed of vsettled solids, when required.

The form of the invention illustrated in Figure 5 attains the sameobjects of the invention, but diiers somewhat in certain particulars,described hereinafter. The principal difference resides in theconstruction of the m'ain truss and the suspension system for Scrapers3l).v k

In this form` the section of the main truss tapers from its outer endtoward its center support,

` and as a consequencavthe `under surface of the truss is spaced` asubstantial distance'from bottom I I, particuarly adjacent central pierI2 `and thereby provide la relatively wide range of movement for beams32 and associated Scrapers 3I.

Inthe various forms4 illustrated, it vusually will be unnecessary Itoprovide more than one driving carriage I9 for the main truss memberI'I,but it will be understood that 4when desired a plurality of such drivingcarriages may be mounted at the ends of the truss sections.

The sectional scraper assembly is common to the various formsillustrated, butis will be understood that the number of such sectionsmay. be two or more as required to meet manufacturing, assemblingv andoperational requirements.

What I claim and desire to secure Iby Letters Patent is: l

1. In la thickener of the traction-drive type, inclusive of a tankhaving an overflow determining a liquidl level in the tank, and a trussmounted for rotary movement in the tank, the improvement which comprisesa plurality of submerged scraper members carried in a depending positionon said truss between its center and outer extremity, each said scrapermember being piv- 1 otally mounted on saidv truss for angular up anddown movement in an ancuate course transverse to the lengthwise axis ofthe truss and being positioned normally in proximity to the bottom ofthe tanzk to urge solids settling thereon centrally a'esafeoe j of thetangens lifting means connected with'` to'andla fee'aiiet, saidpverflowdetermininga each said scraper member and extending'above the Vliquidlevelf-in the-tank for selective yelevationof said scraper members.

a `thicken-'eriofl'thetraction-drive type,

inclusive of atank 'having arifoverflowdetermining a liquid level inthe? tank; and a'ft'russ' mounted for l' rotaryY movement' inl-thetank," the improvementwhich comprises -aplurality of sub-l merged'scraper members lcarried in a idepending position onfsaid'trussfbetweenits center and outer extremityj `each saidscraper member beingpiv-`otally mounted lonv sai-d truss for angular selielevating movement in anarcuate course transverse `tothe lengthwise axis of the truss wheneveran obstruction to its'circumferential move-` ment is encountered, eachsaid scraperbeing posi-1 tioned normally in proximity tothe'bottom ofthe tank ftolurgeA solids; settling thereon centrally of the tank, andlifting means connected with each said scraper member and extendingabove the liquid level in the tank for selective elevation of said`scraper members independently of said selfelevating action.

3. In a thickener of thev traction-drive type,

inclusive of a tank having an overflow determining a liquid level in thetank, anda truss mount-ed for rotary movement in the tank, the improvelment which comprises a plurality, of submerged scraper members carriedin a depending posiselective manual elevation of said scraper members.

4. In a thickener of the traction-drive type, inclusive of a tank andatruss mounted for rotary movement in the tank, the `improvement whichcomprises a plurality of scraper members carried in a depending positionon said truss between its center and `outer extremity, and means forholding each said scraper in said depending position. including a pairof parallel supports pivoted` on the truss and movable through. anelevating `arc in a path transverse to the lengthwise axis of the truss,whenever an obstruction to the circumferential movement of the Scrapersis encountered.

5. In a thickener of the traction-drive type, inclusive of a tank and atruss mounted for .rotary movement in the tank, the improvement whichcomprises a plurality of scraper members carried liquidlevel-inithetank,a central pier in thetank enteriding`` [above the liquid level, l atank-spanning truss journaled for {rotationlfat the upper end oi thepiervfandl supported onjat least one of `its and-sectional scraper"members'depending from the truss in proximity to thetanklbottom to lurgesettledv solids toward said discharge; each" saidA scraper member beingmounted forlimited upi and down movement relative to thetruss in `anarcuate path transverse to thelengthwise axis of-the truss, and meansconnected with `each said scraper member and extending abovethe liquidlevel determined bysaid` overflow for selective `up and down `movementoffsaid scraper members.

7. Traction-type thickener apparatus, comprising a cylindrical tankhaving an endless track on its rim, a peripheral overflow adjacentthereto and a feed inlet, said overflow determining a liquid level inthe tank, a central pier in the tank extending above the liquid level, atankspanning truss journaled for rotation at the upper end of the pierand supported on at least one of its ends by a carriage having wheelstravelling on said track, means on said carriage for driving said Wheelsto rotate the truss, there being a central bottom dischargefrom the tankadjacent the pier, sectional scraper members depending from the truss inproximity to the tank bottom to urge settled solids toward saiddischarge, the respective sections of said scraper members being mountedfor limited up and down movement relative to ,the truss in an arcuatepath moving said sections up and down.

in a depending position onY said truss between its center and outerextremity, and means for holding each said scraper in said dependingposition. including a pair of parallel supports pivoted on the truss andmovable through an elevating arc in a path transverse to the lengthwiseaxis of the truss, whenever an obstruction to the-circumferentialmovement of the Scrapers is encountered, the supports adjacent thecenter of the tank being mounted for movement through a longer arc thanthe supports nearer the periphery of the `tank whereby a greater degreeof elevation is imparted to the associated scraper member.

6. Traction-type thickener apparatus, comprising'a cylindrical tankhaving an endless track` on its rim, a peripheral overflow adjacent`there- 8. In a thickener, inclusive of a tank and a truss mounted forrotary movement in the tank, the improvement which comprises a pluralityof scraper memberscarried in a depending position on said truss betweenits center and outer exl tremity for4 conjoint rotation therewith, said`Scrapers being mounted for differential spacing from the bottom of thetank and in 'proximity thereto to urge solids settling thereon centrallyof the tank, the scraper member nearest the center of the tank beingpositioned at a greater distancev from the bottom of the tank than thescraper members distant from the center of the tank, and having bladesof greater width than the other said Scrapers providing a greaterimpelling surface in said movement of the solids.`

9. In a thickener, a tank, a truss mounted for rotation therein, aplurality of Scrapers suspendied from the truss for conjoint rotationtherewith, and means for supporting each such scraper for individual upand down movement comprising a beam extending through the truss insupporting relation to a depending scraper, means on the truss includingat least two arms pivotally mounted to elevate the` scraper angularly inan arcuate path transverse to the lengthwise axis of` the truss, andmeans on the beam coacting with the truss for limiting the extent ofdownward movement of the beam.

10. In a thickener, a tank, a truss mounted for rotation therein, aplurality of Scrapers suspended from the truss for conjoint rotationtherewith, and means for supporting each such scraper for individual upand down movement comprising a beam extending through the truss insupporting relation to a depending scraper, means on the truss includingtwo arms pivotally mounted to elevate the scraper angularly through anarc transverse to the lengthwise axis of the truss, and coasting meanson the beam and the truss for limiting the extent of up and downmovement of the beam.

11. In a thickener, a tank, a truss mounted for rotation therein, aplurality of Scrapers suspended -from the truss for conjoint rotationtherewith, and means for supporting each such scraper for individual upand down movement comprising a beam extending through the truss insupporting relation to a depending scraper, means on the truss includingtwo arms pivotally mounted to elevate the scraper angularly through anarc transverse to the lengthwise axis of the truss, and a stop member onthe beam coacting with the truss for limiting the extent of downwardmovement of the beam.

12. In a thickener, a tank, a truss mounted for rotation therein, aplurality of Scrapers suspended from the truss for conjoint rotationthere- With, and means for supporting each such scraper for individualup and down movement comprising a beam extending through the truss insupporting relation to a depending scraper, means on the truss includingtWo arms pivotally mounted to elevate the scraper angularly in anarcuate path transverse to the lengthwise axis of the truss, means onthe beam coacting with the truss for limiting the extent of downwardmovement of the beam, and means attached to the beamextending upwardyout of the tank and adapted for connecting with mechanism to raise thescraper in the tank.

. JOHN H. V. FINNEY.

